Recording systems are known in the art wherein a source of radiant energy, such as a high energy beam, is directed to a recording medium and which results in liberation of chemicals such as a dye or dye former in the recording material. The image is thus-formed either in the imaging material at the locations where the imagewise exposure has occurred or in an associated image-receiving layer. A preferred source of exposing radiation is a laser. The use of a laser beam provides a high degree of resolution to the image recorded in the imaging material.
It is known in the art to employ microcapsules which contain a chromogenic material. These microcapsules are responsive to the exposing radiation and, as a function of the exposure, selectively retain or release the chromogenic materials. That is, the methods generally either involve a retention of the chromogenic material as a result of a hardening of the capsules or a material which immobilizes the chromogenic material, or a release of the chromogenic material by a bursting of the capsules upon exposure.
U.S. Pat. No. 4,399,209 issued Aug. 16, 1973 is directed to a transfer imaging system which comprises a layer of microcapsules wherein a chromogenic material is encapsulated with a photosensitive composition. The photosensitive composition comprises a radiation-curable composition which upon exposure causes an increase in its viscosity thereby preventing diffusion of the chromogenic material upon rupture of the capsule. Upon rupture of the capsules, those capsules in which the radiation-curable material was not activated will release the chromogenic material which will transfer to a developer sheet and react with the developer material to form the image. Similar imaging systems are described in U.S. Pat. Nos. 4,440,846 and 4,489,151. A color imaging system employing the aforementioned photosensitive composition encapsulated in pressure-rupturable microcapsules is described in British Pat. No. 2,113,860 published Aug. 10, 1983.